Free date tool

Week Number Today

Free week number tool: see what week of the year it is right now, look up the week number for any date, and compare the US and ISO conventions.

Start FreeNeed the ISO week number?

What week is it?

Pick any date to see its week number. The default is today, so you get the current week straight away.

Week number (weeks start Sunday)31
ISO 8601 week31
Day of the year210
Weeks left this year22

This page counts weeks the North American way: weeks start on Sunday and the week containing January 1 is week 1. Most of Europe and business software use the ISO week instead, which can differ by one.

See the ISO week numberCount working daysPlan across time zones
2026

All weeks in 2026

  1. Week 1Sun, Dec 28 - Sat, Jan 3
  2. Week 2Sun, Jan 4 - Sat, Jan 10
  3. Week 3Sun, Jan 11 - Sat, Jan 17
  4. Week 4Sun, Jan 18 - Sat, Jan 24
  5. Week 5Sun, Jan 25 - Sat, Jan 31
  6. Week 6Sun, Feb 1 - Sat, Feb 7
  7. Week 7Sun, Feb 8 - Sat, Feb 14
  8. Week 8Sun, Feb 15 - Sat, Feb 21
  9. Week 9Sun, Feb 22 - Sat, Feb 28
  10. Week 10Sun, Mar 1 - Sat, Mar 7
  11. Week 11Sun, Mar 8 - Sat, Mar 14
  12. Week 12Sun, Mar 15 - Sat, Mar 21
  13. Week 13Sun, Mar 22 - Sat, Mar 28
  14. Week 14Sun, Mar 29 - Sat, Apr 4
  15. Week 15Sun, Apr 5 - Sat, Apr 11
  16. Week 16Sun, Apr 12 - Sat, Apr 18
  17. Week 17Sun, Apr 19 - Sat, Apr 25
  18. Week 18Sun, Apr 26 - Sat, May 2
  19. Week 19Sun, May 3 - Sat, May 9
  20. Week 20Sun, May 10 - Sat, May 16
  21. Week 21Sun, May 17 - Sat, May 23
  22. Week 22Sun, May 24 - Sat, May 30
  23. Week 23Sun, May 31 - Sat, Jun 6
  24. Week 24Sun, Jun 7 - Sat, Jun 13
  25. Week 25Sun, Jun 14 - Sat, Jun 20
  26. Week 26Sun, Jun 21 - Sat, Jun 27
  27. Week 27Sun, Jun 28 - Sat, Jul 4
  28. Week 28Sun, Jul 5 - Sat, Jul 11
  29. Week 29Sun, Jul 12 - Sat, Jul 18
  30. Week 30Sun, Jul 19 - Sat, Jul 25
  31. Week 31Sun, Jul 26 - Sat, Aug 1
  32. Week 32Sun, Aug 2 - Sat, Aug 8
  33. Week 33Sun, Aug 9 - Sat, Aug 15
  34. Week 34Sun, Aug 16 - Sat, Aug 22
  35. Week 35Sun, Aug 23 - Sat, Aug 29
  36. Week 36Sun, Aug 30 - Sat, Sep 5
  37. Week 37Sun, Sep 6 - Sat, Sep 12
  38. Week 38Sun, Sep 13 - Sat, Sep 19
  39. Week 39Sun, Sep 20 - Sat, Sep 26
  40. Week 40Sun, Sep 27 - Sat, Oct 3
  41. Week 41Sun, Oct 4 - Sat, Oct 10
  42. Week 42Sun, Oct 11 - Sat, Oct 17
  43. Week 43Sun, Oct 18 - Sat, Oct 24
  44. Week 44Sun, Oct 25 - Sat, Oct 31
  45. Week 45Sun, Nov 1 - Sat, Nov 7
  46. Week 46Sun, Nov 8 - Sat, Nov 14
  47. Week 47Sun, Nov 15 - Sat, Nov 21
  48. Week 48Sun, Nov 22 - Sat, Nov 28
  49. Week 49Sun, Nov 29 - Sat, Dec 5
  50. Week 50Sun, Dec 6 - Sat, Dec 12
  51. Week 51Sun, Dec 13 - Sat, Dec 19
  52. Week 52Sun, Dec 20 - Sat, Dec 26
  53. Week 53Sun, Dec 27 - Sat, Jan 2

How week numbers work

A week number tells you which week of the year a date falls in, from 1 near January up to 52 or 53 near December. It is a compact way to refer to a stretch of time - "week 31" instead of a full date range - which is why teams use it for planning, reporting, and payroll periods.

There is more than one convention. The North American count starts weeks on Sunday and puts January 1 in week 1. The ISO 8601 count, common in Europe and in business tools, starts weeks on Monday and ties week 1 to the year's first Thursday. Near the turn of the year the two can disagree by a week, so it is worth knowing which one your calendar uses.

Whether a year has 52 or 53 numbered weeks depends on the weekday of January 1 and whether it is a leap year. In this Sunday-start count the week containing January 1 is always week 1, even when it begins in late December, and the last week can run a few days into January of the next year.

Check the ISO week numberBrowse all free tools

Get the week number in Excel or Google Sheets

Both Excel and Google Sheets have a WEEKNUM function that returns this Sunday-start week number. Give it a date and it returns the week of the year.

=WEEKNUM(TODAY())=WEEKNUM(A2)

The optional second argument sets which day the week starts on: 1, the default, starts weeks on Sunday, and 2 starts them on Monday. For the ISO week number, use ISOWEEKNUM instead, or WEEKNUM with a return type of 21.

Week number questions

What week number is it right now?

The current week number is shown at the top of this page and updates automatically. It uses the Sunday-start convention, where the week that contains January 1 is week 1.

How many weeks are in a year?

A year has 52 or 53 numbered weeks. Most years have 52; a year gets a 53rd week when its days run past 52 full weeks, which depends on the starting weekday and leap years.

Why does my calendar show a different week number?

Different systems number weeks differently. This page uses the North American Sunday-start count. Europe and most business software use the ISO 8601 count, which starts weeks on Monday and can differ by one, especially around New Year.

How do I find the week number for a past or future date?

Enter any date in the date box above. The page shows its week number in both the Sunday-start and ISO conventions and highlights it in the week list below.